Some painted walls, others cleaned a preschool inside and out. Others pulled yard cleanup duty. All told, there were more than 12,000 of them -- people who came out on Sept. 21, United Way of King County's biggest ever Day of Caring.

If Charles Darwin and the Dalai Lama could chat, they would agree on why humans are compassionate, psychologist Paul Eckman says. "We are compelled to relieve the sufferings of another, in order that our own painful feelings may be at the same time relieved," Darwin wrote.

The Dalai Lama says "the seed of compassion" is the discomfort we experience when we see someone suffering. "We are thus impelled to relieve the suffering of another so that our own painful suffering may be relieved."